Machine for grinding the runners of skates and the like



Dec. '2, 1941. J 2,264,676

MACHINE FOR GRINDING THE RUNNERS OF SKATES AND THE LIKE Filed Oct. 28, 1939 2' Sheets-Sheet 1 Flay?! Q F1972.

Johan o'lmzad JL OSTBLAD Dec. 2, 1941.

MACHINE FOR GRINDING THE RUNNERS OF SKATES AND THE LIKE 2 Sheets-Sheet 2 Filed 001:. 28, 1939 han OJlb/ad I? for eg Patented Dec. 2, 1941 UITED STATES PTENT QFFICE Johan fistblad, Jarna, Sweden Application October 28, 1939, Serial No. 301,825 In Sweden November 9, 1938 1 Claim.

The present invention relates to an improvement in grinding machines for grinding hollow or flute-shaped running faces of the runners of skates and the like, of the type which comprise a rotary grinding wheel having a convex grinding face, and a holder which carries guiding means for guiding the skate runner during the grinding, the said holder being pivotally journalled in the machine frame in such manner that it may be turned during the grinding operation on an axis which forms right angles to the axis of rotation of the grinding wheel. The purpose of this arrangement is to make it possible also for unskilled labourers to perform the grinding operation accurately. According to a prior construction, the guiding means for guiding the skate runner during the grindin operation consisted of two rollers rotatably journalled in the holder and the peripheries of which are preferably covered with rubber or the like, the said rollers being located at a distance from one another leaving an intermediate space in which the skate runner may be moved to and fro during the grinding operation.

The present improvement has for its purpose to provide means for guiding the skate runner during the grinding operation in a still more efficient way than that possible by means of the abovementioned rollers alone.

With this purpose in view the present improvement resides mainly in the holder, which is pivotally journalled in the machine frame, being provided with guides secured to the holder, and on or in which a slide is slidable, which slide carries a clamping device in which the skate runner to be ground may be secured, in such manner that said runner is always held in one and the same predetermined plane relatively to the holder while it is moved to and fro during the grinding operation in a direction substan tially tangential to the grinding wheel. The clamping device may suitably be pivotally connected to an arm or the like which in its turn is pivotally connected to the movable slide, so that the skate runner secured in the clamp may be moved in the said predetermined plane relatively to the holder while it is moved to and fro along the guides.

A constructional form of the invention is illustrated in the accompanying drawings by way of example. Figs. 1 and 2 show, in front view and in side view, respectively, the guiding means attached to the pivoted holder. Figs. 3

and 4 show to a larger scale the holder and the 55 bars is Slide 20 associated members of the grinding machine. in rear view and in side view, respectively.

Referring to the drawings, l denotes a por tion of the frame of the grinding machine which supports a bearing 2 for the shaft 3 of the grinding wheel 4, said shaft being rotated by any suitable means, such as a belt pulley, or a motor, not illustrated in the drawings.

Mounted on the machine frame I is a member 5 which is adjustably secured to the frame by means of two bolts 6, which extend through a slot I in the machine frame, so that after loosening said bolts, the member 5 may be adjusted in the direction towards and away from the bearing 2. The said member 5 carries the holder 8 which is pivotally journalled in said member 5 by means of a bolt 9 which extends through a bearing bushing Ill rigidly connected to the member 5, and which is screwed into the lower side of the holder 8, so that in this manner the holder B is capable of turning about the axis of the bolt 9 which lies in, or substantially in, the central radial plane through the grinding wheel and crosses the axis of the wheel in the space. The lower end of the bolt 9 carries a pair of nuts II, and a spring I2 is interposed between said nuts and the lower end of the bushing I0, which spring maintains the holder 8 bearing against the upper face of the member 5. Secured to one side of the holder 8 is a projecting arm l3 which serves as a handle for turning the holder 8 on the bolt 9. The holder 8 is provided with a groove M for receiving the skate runner IE to be ground, and two guide rollers l6 are rotatably journalled at the upper end of the holder on either side of the said groove. These rollers are provided at their peripheries with rings l! of rubber or a similar soft material, and are located at such distance from one another that there is an intermediate space in which the skate runner l5 may be moved up and down during the grinding operation, see Figs. 1 and 3.

In order to obtain a still more positive guiding of the skate runner I5 during the grinding operation than that provided by the rollers l6, I! alone, which rollers cannot securely prevent the skate runner from rocking in the lateral direction, the pivoted holder 8 is provided, according to the present invention, with guides which, in the instance illustrated, consist of two parallel bars l8 the upper ends of which are securely connected to one another by means of a cross-piece l9. Movable along these guide which grips around the two bars in the manner illustrated in Figs. 1 and 2. An arm 2i is pivoted to the said slide 20 in such manner that it is capable of turning in a radial plane through the axis of the bolt 9, which plane is located centrally between the two guide bars l8 and is perpendicular to the plane through said bars. Pivotally attached to the free end of the arm 2| is a clamping device 22 having two jaws 23 which-may be pressed against one anotherby means of a screw 24, so that the skate runner l5 to be ground may be secured between said jaws. The cross-piece I9 is provided with a hook 25 on which the clamping device 22, 23 may be hung-up when the machine is not used.

As previously stated, the holder *8 maybe turned about the axis of the bolt 9 by means of the handle IS.

The skate runner to be ground is-placed in the groove I4 and in the opening intermediate the guide rollers l6, l1, and its upper end is secured in the clampingdevice'22, '23, see Fig. 2. This clamping device together with the twogu-ide rollers always maintainthe skate-runner in one and the same predetermined plane relatively to the guide bars I 8 and thus to the holder 8, namely in the above-mentioned radial plane passing centrally between said guide bars, and the runner is thus 'prevented'from rocking in the lateral directionwhileit is moved up and down during 'the grindingoperation. In this way the skate runner is 'so'effectively guided that the grinding operation can "be performed without difficulty also byan unskilled labourer. The pivotal connections between the clamping device 22, '23 and the arm 21 and between the latter and the guide 22 render it possible to swing or move the skate runner l5 secured in the clamping device to and froto the right and to the left in Fig. 2-to the extent required in order to make it possible al- Ways to hold the edge of the skate runner, notwithstanding its curved shape, against the grinding wheel at the most suitable angle. The holder 8 being movable about its pivot, it is possible to utilize the entire grinding face of the grinding wheel 4 so that the same will be subjected to uniform wear.

The constructional form above described and illustrated in the drawings is only to be regarded as. an arample, and it will be understood that its detailsmay be modified in several ways without departing from the principle of the invention.

I claim:

In-a grinding machine having a frame, a grinding wheel with a convex grinding face rotatably journalled in said frame, and a holder pivotally mounted in said frame with its axis of rotation coinciding substantially with the central radial plane throughsaid grinding wheel, the combination of a pair of slide-carrying j uide' barsrigid with said holder and extending therefrom'in substantial alignment therewith, a slide piece bridging saidguide bars in'slidable engagement therewith, an arm pivoted to said slide piece "and swingable between said guide bars in aplane substantially radial to the axisof said holder, and clamping means pivoted'to said arm and adapted pivotally to engage an article to be ground so as to permit such article to'be moved'both longitudinally of said guidebars and radially. relatively to'the axis ofsaid holder.

JOHAN osTBnAD. 

